German Patent Disclosure Document No. DE-OS 20 52 806 describes a printing machine inker in which a plurality of milling rollers, cooperating with an ink application roller, has doctor blades associated therewith. Ink which is stripped from the respective milling rollers is returned to an ink retention vessel. In operation, ink is applied to the respective rollers of the ink train such that more ink is supplied than necessary to ink the plate for printing. Initially, the ink application roller receives an ink layer which is substantially thicker than necessary. This ink layer is then split by the subsequent milling rollers and the ink which is removed from the application roller is stripped off the milling rollers and returned to the ink supply.
It has been found that the actually required ink for the application roller and/or the plate cannot be accurately determined by such a system. Applying a doctor blades to the rollers and/or controlling the operating time and strokes of a ductor roller from an ink trough cannot accurately control the uniformity, or smoothness of the ink supply. Rather, it is necessary to provide multiple splitting of the ink film between the application roller and the respective milling rollers in engagement therewith. However, any uneven ink distribution or ink strips or spots forming peaks and valleys of the ink firlm cannot be completely removed since the ink on the application roller is split at each milling roller into two partial films of equal thickness so that, in general principle, any uneven ink distribution will remain, although to a somewhat decreased absolute extent, while the percentage of change in thickness between the remaining film will continue to be present.